| /* |
| * Copyright © 2014 Intel Corporation |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a |
| * copy of this software and associated documentation files (the "Software"), |
| * to deal in the Software without restriction, including without limitation |
| * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
| * and/or sell copies of the Software, and to permit persons to whom the |
| * Software is furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice (including the next |
| * paragraph) shall be included in all copies or substantial portions of the |
| * Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS |
| * IN THE SOFTWARE. |
| * |
| * This code is based on original work by Ilia Mirkin. |
| */ |
| |
| /** |
| * \file gen6_gs_visitor.cpp |
| * |
| * Gen6 geometry shader implementation |
| */ |
| |
| #include "gen6_gs_visitor.h" |
| #include "brw_eu.h" |
| |
| namespace brw { |
| |
| void |
| gen6_gs_visitor::emit_prolog() |
| { |
| vec4_gs_visitor::emit_prolog(); |
| |
| /* Gen6 geometry shaders require to allocate an initial VUE handle via |
| * FF_SYNC message, however the documentation remarks that only one thread |
| * can write to the URB simultaneously and the FF_SYNC message provides the |
| * synchronization mechanism for this, so using this message effectively |
| * stalls the thread until it is its turn to write to the URB. Because of |
| * this, the best way to implement geometry shader algorithms in gen6 is to |
| * execute the algorithm before the FF_SYNC message to maximize parallelism. |
| * |
| * To achieve this we buffer the geometry shader outputs for each emitted |
| * vertex in vertex_output during operation. Then, when we have processed |
| * the last vertex (that is, at thread end time), we send the FF_SYNC |
| * message to allocate the initial VUE handle and write all buffered vertex |
| * data to the URB in one go. |
| * |
| * For each emitted vertex, vertex_output will hold vue_map.num_slots |
| * data items plus one additional item to hold required flags |
| * (PrimType, PrimStart, PrimEnd, as expected by the URB_WRITE message) |
| * which come right after the data items for that vertex. Vertex data and |
| * flags for the next vertex come right after the data items and flags for |
| * the previous vertex. |
| */ |
| this->current_annotation = "gen6 prolog"; |
| this->vertex_output = src_reg(this, |
| glsl_type::uint_type, |
| (prog_data->vue_map.num_slots + 1) * |
| nir->info->gs.vertices_out); |
| this->vertex_output_offset = src_reg(this, glsl_type::uint_type); |
| emit(MOV(dst_reg(this->vertex_output_offset), brw_imm_ud(0u))); |
| |
| /* MRF 1 will be the header for all messages (FF_SYNC and URB_WRITES), |
| * so initialize it once to R0. |
| */ |
| vec4_instruction *inst = emit(MOV(dst_reg(MRF, 1), |
| retype(brw_vec8_grf(0, 0), |
| BRW_REGISTER_TYPE_UD))); |
| inst->force_writemask_all = true; |
| |
| /* This will be used as a temporary to store writeback data of FF_SYNC |
| * and URB_WRITE messages. |
| */ |
| this->temp = src_reg(this, glsl_type::uint_type); |
| |
| /* This will be used to know when we are processing the first vertex of |
| * a primitive. We will set this to URB_WRITE_PRIM_START only when we know |
| * that we are processing the first vertex in the primitive and to zero |
| * otherwise. This way we can use its value directly in the URB write |
| * headers. |
| */ |
| this->first_vertex = src_reg(this, glsl_type::uint_type); |
| emit(MOV(dst_reg(this->first_vertex), brw_imm_ud(URB_WRITE_PRIM_START))); |
| |
| /* The FF_SYNC message requires to know the number of primitives generated, |
| * so keep a counter for this. |
| */ |
| this->prim_count = src_reg(this, glsl_type::uint_type); |
| emit(MOV(dst_reg(this->prim_count), brw_imm_ud(0u))); |
| |
| if (prog->info.has_transform_feedback_varyings) { |
| /* Create a virtual register to hold destination indices in SOL */ |
| this->destination_indices = src_reg(this, glsl_type::uvec4_type); |
| /* Create a virtual register to hold number of written primitives */ |
| this->sol_prim_written = src_reg(this, glsl_type::uint_type); |
| /* Create a virtual register to hold Streamed Vertex Buffer Indices */ |
| this->svbi = src_reg(this, glsl_type::uvec4_type); |
| /* Create a virtual register to hold max values of SVBI */ |
| this->max_svbi = src_reg(this, glsl_type::uvec4_type); |
| emit(MOV(dst_reg(this->max_svbi), |
| src_reg(retype(brw_vec1_grf(1, 4), BRW_REGISTER_TYPE_UD)))); |
| |
| xfb_setup(); |
| } |
| |
| /* PrimitveID is delivered in r0.1 of the thread payload. If the program |
| * needs it we have to move it to a separate register where we can map |
| * the atttribute. |
| * |
| * Notice that we cannot use a virtual register for this, because we need to |
| * map all input attributes to hardware registers in setup_payload(), |
| * which happens before virtual registers are mapped to hardware registers. |
| * We could work around that issue if we were able to compute the first |
| * non-payload register here and move the PrimitiveID information to that |
| * register, but we can't because at this point we don't know the final |
| * number uniforms that will be included in the payload. |
| * |
| * So, what we do is to place PrimitiveID information in r1, which is always |
| * delivered as part of the payload, but its only populated with data |
| * relevant for transform feedback when we set GEN6_GS_SVBI_PAYLOAD_ENABLE |
| * in the 3DSTATE_GS state packet. That information can be obtained by other |
| * means though, so we can safely use r1 for this purpose. |
| */ |
| if (gs_prog_data->include_primitive_id) { |
| this->primitive_id = |
| src_reg(retype(brw_vec8_grf(1, 0), BRW_REGISTER_TYPE_UD)); |
| emit(GS_OPCODE_SET_PRIMITIVE_ID, dst_reg(this->primitive_id)); |
| } |
| } |
| |
| void |
| gen6_gs_visitor::gs_emit_vertex(int stream_id) |
| { |
| this->current_annotation = "gen6 emit vertex"; |
| |
| /* Buffer all output slots for this vertex in vertex_output */ |
| for (int slot = 0; slot < prog_data->vue_map.num_slots; ++slot) { |
| int varying = prog_data->vue_map.slot_to_varying[slot]; |
| if (varying != VARYING_SLOT_PSIZ) { |
| dst_reg dst(this->vertex_output); |
| dst.reladdr = ralloc(mem_ctx, src_reg); |
| memcpy(dst.reladdr, &this->vertex_output_offset, sizeof(src_reg)); |
| emit_urb_slot(dst, varying); |
| } else { |
| /* The PSIZ slot can pack multiple varyings in different channels |
| * and emit_urb_slot() will produce a MOV instruction for each of |
| * them. Since we are writing to an array, that will translate to |
| * possibly multiple MOV instructions with an array destination and |
| * each will generate a scratch write with the same offset into |
| * scratch space (thus, each one overwriting the previous). This is |
| * not what we want. What we will do instead is emit PSIZ to a |
| * a regular temporary register, then move that resgister into the |
| * array. This way we only have one instruction with an array |
| * destination and we only produce a single scratch write. |
| */ |
| dst_reg tmp = dst_reg(src_reg(this, glsl_type::uvec4_type)); |
| emit_urb_slot(tmp, varying); |
| dst_reg dst(this->vertex_output); |
| dst.reladdr = ralloc(mem_ctx, src_reg); |
| memcpy(dst.reladdr, &this->vertex_output_offset, sizeof(src_reg)); |
| vec4_instruction *inst = emit(MOV(dst, src_reg(tmp))); |
| inst->force_writemask_all = true; |
| } |
| |
| emit(ADD(dst_reg(this->vertex_output_offset), |
| this->vertex_output_offset, brw_imm_ud(1u))); |
| } |
| |
| /* Now buffer flags for this vertex */ |
| dst_reg dst(this->vertex_output); |
| dst.reladdr = ralloc(mem_ctx, src_reg); |
| memcpy(dst.reladdr, &this->vertex_output_offset, sizeof(src_reg)); |
| if (nir->info->gs.output_primitive == GL_POINTS) { |
| /* If we are outputting points, then every vertex has PrimStart and |
| * PrimEnd set. |
| */ |
| emit(MOV(dst, brw_imm_d((_3DPRIM_POINTLIST << URB_WRITE_PRIM_TYPE_SHIFT) | |
| URB_WRITE_PRIM_START | URB_WRITE_PRIM_END))); |
| emit(ADD(dst_reg(this->prim_count), this->prim_count, brw_imm_ud(1u))); |
| } else { |
| /* Otherwise, we can only set the PrimStart flag, which we have stored |
| * in the first_vertex register. We will have to wait until we execute |
| * EndPrimitive() or we end the thread to set the PrimEnd flag on a |
| * vertex. |
| */ |
| emit(OR(dst, this->first_vertex, |
| brw_imm_ud(gs_prog_data->output_topology << |
| URB_WRITE_PRIM_TYPE_SHIFT))); |
| emit(MOV(dst_reg(this->first_vertex), brw_imm_ud(0u))); |
| } |
| emit(ADD(dst_reg(this->vertex_output_offset), |
| this->vertex_output_offset, brw_imm_ud(1u))); |
| } |
| |
| void |
| gen6_gs_visitor::gs_end_primitive() |
| { |
| this->current_annotation = "gen6 end primitive"; |
| /* Calling EndPrimitive() is optional for point output. In this case we set |
| * the PrimEnd flag when we process EmitVertex(). |
| */ |
| if (nir->info->gs.output_primitive == GL_POINTS) |
| return; |
| |
| /* Otherwise we know that the last vertex we have processed was the last |
| * vertex in the primitive and we need to set its PrimEnd flag, so do this |
| * unless we haven't emitted that vertex at all (vertex_count != 0). |
| * |
| * Notice that we have already incremented vertex_count when we processed |
| * the last emit_vertex, so we need to take that into account in the |
| * comparison below (hence the num_output_vertices + 1 in the comparison |
| * below). |
| */ |
| unsigned num_output_vertices = nir->info->gs.vertices_out; |
| emit(CMP(dst_null_ud(), this->vertex_count, |
| brw_imm_ud(num_output_vertices + 1), BRW_CONDITIONAL_L)); |
| vec4_instruction *inst = emit(CMP(dst_null_ud(), |
| this->vertex_count, brw_imm_ud(0u), |
| BRW_CONDITIONAL_NEQ)); |
| inst->predicate = BRW_PREDICATE_NORMAL; |
| emit(IF(BRW_PREDICATE_NORMAL)); |
| { |
| /* vertex_output_offset is already pointing at the first entry of the |
| * next vertex. So subtract 1 to modify the flags for the previous |
| * vertex. |
| */ |
| src_reg offset(this, glsl_type::uint_type); |
| emit(ADD(dst_reg(offset), this->vertex_output_offset, brw_imm_d(-1))); |
| |
| src_reg dst(this->vertex_output); |
| dst.reladdr = ralloc(mem_ctx, src_reg); |
| memcpy(dst.reladdr, &offset, sizeof(src_reg)); |
| |
| emit(OR(dst_reg(dst), dst, brw_imm_d(URB_WRITE_PRIM_END))); |
| emit(ADD(dst_reg(this->prim_count), this->prim_count, brw_imm_ud(1u))); |
| |
| /* Set the first vertex flag to indicate that the next vertex will start |
| * a primitive. |
| */ |
| emit(MOV(dst_reg(this->first_vertex), brw_imm_d(URB_WRITE_PRIM_START))); |
| } |
| emit(BRW_OPCODE_ENDIF); |
| } |
| |
| void |
| gen6_gs_visitor::emit_urb_write_header(int mrf) |
| { |
| this->current_annotation = "gen6 urb header"; |
| /* Compute offset of the flags for the current vertex in vertex_output and |
| * write them in dw2 of the message header. |
| * |
| * Notice that by the time that emit_thread_end() calls here |
| * vertex_output_offset should point to the first data item of the current |
| * vertex in vertex_output, thus we only need to add the number of output |
| * slots per vertex to that offset to obtain the flags data offset. |
| */ |
| src_reg flags_offset(this, glsl_type::uint_type); |
| emit(ADD(dst_reg(flags_offset), |
| this->vertex_output_offset, |
| brw_imm_d(prog_data->vue_map.num_slots))); |
| |
| src_reg flags_data(this->vertex_output); |
| flags_data.reladdr = ralloc(mem_ctx, src_reg); |
| memcpy(flags_data.reladdr, &flags_offset, sizeof(src_reg)); |
| |
| emit(GS_OPCODE_SET_DWORD_2, dst_reg(MRF, mrf), flags_data); |
| } |
| |
| static int |
| align_interleaved_urb_mlen(int mlen) |
| { |
| /* URB data written (does not include the message header reg) must |
| * be a multiple of 256 bits, or 2 VS registers. See vol5c.5, |
| * section 5.4.3.2.2: URB_INTERLEAVED. |
| */ |
| if ((mlen % 2) != 1) |
| mlen++; |
| return mlen; |
| } |
| |
| void |
| gen6_gs_visitor::emit_urb_write_opcode(bool complete, int base_mrf, |
| int last_mrf, int urb_offset) |
| { |
| vec4_instruction *inst = NULL; |
| |
| if (!complete) { |
| /* If the vertex is not complete we don't have to do anything special */ |
| inst = emit(GS_OPCODE_URB_WRITE); |
| inst->urb_write_flags = BRW_URB_WRITE_NO_FLAGS; |
| } else { |
| /* Otherwise we always request to allocate a new VUE handle. If this is |
| * the last write before the EOT message and the new handle never gets |
| * used it will be dereferenced when we send the EOT message. This is |
| * necessary to avoid different setups for the EOT message (one for the |
| * case when there is no output and another for the case when there is) |
| * which would require to end the program with an IF/ELSE/ENDIF block, |
| * something we do not want. |
| */ |
| inst = emit(GS_OPCODE_URB_WRITE_ALLOCATE); |
| inst->urb_write_flags = BRW_URB_WRITE_COMPLETE; |
| inst->dst = dst_reg(MRF, base_mrf); |
| inst->src[0] = this->temp; |
| } |
| |
| inst->base_mrf = base_mrf; |
| inst->mlen = align_interleaved_urb_mlen(last_mrf - base_mrf); |
| inst->offset = urb_offset; |
| } |
| |
| void |
| gen6_gs_visitor::emit_thread_end() |
| { |
| /* Make sure the current primitive is ended: we know it is not ended when |
| * first_vertex is not zero. This is only relevant for outputs other than |
| * points because in the point case we set PrimEnd on all vertices. |
| */ |
| if (nir->info->gs.output_primitive != GL_POINTS) { |
| emit(CMP(dst_null_ud(), this->first_vertex, brw_imm_ud(0u), BRW_CONDITIONAL_Z)); |
| emit(IF(BRW_PREDICATE_NORMAL)); |
| gs_end_primitive(); |
| emit(BRW_OPCODE_ENDIF); |
| } |
| |
| /* Here we have to: |
| * 1) Emit an FF_SYNC messsage to obtain an initial VUE handle. |
| * 2) Loop over all buffered vertex data and write it to corresponding |
| * URB entries. |
| * 3) Allocate new VUE handles for all vertices other than the first. |
| * 4) Send a final EOT message. |
| */ |
| |
| /* MRF 0 is reserved for the debugger, so start with message header |
| * in MRF 1. |
| */ |
| int base_mrf = 1; |
| |
| /* In the process of generating our URB write message contents, we |
| * may need to unspill a register or load from an array. Those |
| * reads would use MRFs 21..23 |
| */ |
| int max_usable_mrf = FIRST_SPILL_MRF(devinfo->gen); |
| |
| /* Issue the FF_SYNC message and obtain the initial VUE handle. */ |
| emit(CMP(dst_null_ud(), this->vertex_count, brw_imm_ud(0u), BRW_CONDITIONAL_G)); |
| emit(IF(BRW_PREDICATE_NORMAL)); |
| { |
| this->current_annotation = "gen6 thread end: ff_sync"; |
| |
| vec4_instruction *inst; |
| if (prog->info.has_transform_feedback_varyings) { |
| src_reg sol_temp(this, glsl_type::uvec4_type); |
| emit(GS_OPCODE_FF_SYNC_SET_PRIMITIVES, |
| dst_reg(this->svbi), |
| this->vertex_count, |
| this->prim_count, |
| sol_temp); |
| inst = emit(GS_OPCODE_FF_SYNC, |
| dst_reg(this->temp), this->prim_count, this->svbi); |
| } else { |
| inst = emit(GS_OPCODE_FF_SYNC, |
| dst_reg(this->temp), this->prim_count, brw_imm_ud(0u)); |
| } |
| inst->base_mrf = base_mrf; |
| |
| /* Loop over all buffered vertices and emit URB write messages */ |
| this->current_annotation = "gen6 thread end: urb writes init"; |
| src_reg vertex(this, glsl_type::uint_type); |
| emit(MOV(dst_reg(vertex), brw_imm_ud(0u))); |
| emit(MOV(dst_reg(this->vertex_output_offset), brw_imm_ud(0u))); |
| |
| this->current_annotation = "gen6 thread end: urb writes"; |
| emit(BRW_OPCODE_DO); |
| { |
| emit(CMP(dst_null_d(), vertex, this->vertex_count, BRW_CONDITIONAL_GE)); |
| inst = emit(BRW_OPCODE_BREAK); |
| inst->predicate = BRW_PREDICATE_NORMAL; |
| |
| /* First we prepare the message header */ |
| emit_urb_write_header(base_mrf); |
| |
| /* Then add vertex data to the message in interleaved fashion */ |
| int slot = 0; |
| bool complete = false; |
| do { |
| int mrf = base_mrf + 1; |
| |
| /* URB offset is in URB row increments, and each of our MRFs is half |
| * of one of those, since we're doing interleaved writes. |
| */ |
| int urb_offset = slot / 2; |
| |
| for (; slot < prog_data->vue_map.num_slots; ++slot) { |
| int varying = prog_data->vue_map.slot_to_varying[slot]; |
| current_annotation = output_reg_annotation[varying]; |
| |
| /* Compute offset of this slot for the current vertex |
| * in vertex_output |
| */ |
| src_reg data(this->vertex_output); |
| data.reladdr = ralloc(mem_ctx, src_reg); |
| memcpy(data.reladdr, &this->vertex_output_offset, |
| sizeof(src_reg)); |
| |
| /* Copy this slot to the appropriate message register */ |
| dst_reg reg = dst_reg(MRF, mrf); |
| reg.type = output_reg[varying][0].type; |
| data.type = reg.type; |
| vec4_instruction *inst = emit(MOV(reg, data)); |
| inst->force_writemask_all = true; |
| |
| mrf++; |
| emit(ADD(dst_reg(this->vertex_output_offset), |
| this->vertex_output_offset, brw_imm_ud(1u))); |
| |
| /* If this was max_usable_mrf, we can't fit anything more into |
| * this URB WRITE. Same if we reached the max. message length. |
| */ |
| if (mrf > max_usable_mrf || |
| align_interleaved_urb_mlen(mrf - base_mrf + 1) > BRW_MAX_MSG_LENGTH) { |
| slot++; |
| break; |
| } |
| } |
| |
| complete = slot >= prog_data->vue_map.num_slots; |
| emit_urb_write_opcode(complete, base_mrf, mrf, urb_offset); |
| } while (!complete); |
| |
| /* Skip over the flags data item so that vertex_output_offset points |
| * to the first data item of the next vertex, so that we can start |
| * writing the next vertex. |
| */ |
| emit(ADD(dst_reg(this->vertex_output_offset), |
| this->vertex_output_offset, brw_imm_ud(1u))); |
| |
| emit(ADD(dst_reg(vertex), vertex, brw_imm_ud(1u))); |
| } |
| emit(BRW_OPCODE_WHILE); |
| |
| if (prog->info.has_transform_feedback_varyings) |
| xfb_write(); |
| } |
| emit(BRW_OPCODE_ENDIF); |
| |
| /* Finally, emit EOT message. |
| * |
| * In gen6 we need to end the thread differently depending on whether we have |
| * emitted at least one vertex or not. In case we did, the EOT message must |
| * always include the COMPLETE flag or else the GPU hangs. If we have not |
| * produced any output we can't use the COMPLETE flag. |
| * |
| * However, this would lead us to end the program with an ENDIF opcode, |
| * which we want to avoid, so what we do is that we always request a new |
| * VUE handle every time we do a URB WRITE, even for the last vertex we emit. |
| * With this we make sure that whether we have emitted at least one vertex |
| * or none at all, we have to finish the thread without writing to the URB, |
| * which works for both cases by setting the COMPLETE and UNUSED flags in |
| * the EOT message. |
| */ |
| this->current_annotation = "gen6 thread end: EOT"; |
| |
| if (prog->info.has_transform_feedback_varyings) { |
| /* When emitting EOT, set SONumPrimsWritten Increment Value. */ |
| src_reg data(this, glsl_type::uint_type); |
| emit(AND(dst_reg(data), this->sol_prim_written, brw_imm_ud(0xffffu))); |
| emit(SHL(dst_reg(data), data, brw_imm_ud(16u))); |
| emit(GS_OPCODE_SET_DWORD_2, dst_reg(MRF, base_mrf), data); |
| } |
| |
| vec4_instruction *inst = emit(GS_OPCODE_THREAD_END); |
| inst->urb_write_flags = BRW_URB_WRITE_COMPLETE | BRW_URB_WRITE_UNUSED; |
| inst->base_mrf = base_mrf; |
| inst->mlen = 1; |
| } |
| |
| void |
| gen6_gs_visitor::setup_payload() |
| { |
| int attribute_map[BRW_VARYING_SLOT_COUNT * MAX_GS_INPUT_VERTICES]; |
| |
| /* Attributes are going to be interleaved, so one register contains two |
| * attribute slots. |
| */ |
| int attributes_per_reg = 2; |
| |
| /* If a geometry shader tries to read from an input that wasn't written by |
| * the vertex shader, that produces undefined results, but it shouldn't |
| * crash anything. So initialize attribute_map to zeros--that ensures that |
| * these undefined results are read from r0. |
| */ |
| memset(attribute_map, 0, sizeof(attribute_map)); |
| |
| int reg = 0; |
| |
| /* The payload always contains important data in r0. */ |
| reg++; |
| |
| /* r1 is always part of the payload and it holds information relevant |
| * for transform feedback when we set the GEN6_GS_SVBI_PAYLOAD_ENABLE bit in |
| * the 3DSTATE_GS packet. We will overwrite it with the PrimitiveID |
| * information (and move the original value to a virtual register if |
| * necessary). |
| */ |
| if (gs_prog_data->include_primitive_id) |
| attribute_map[VARYING_SLOT_PRIMITIVE_ID] = attributes_per_reg * reg; |
| reg++; |
| |
| reg = setup_uniforms(reg); |
| |
| reg = setup_varying_inputs(reg, attribute_map, attributes_per_reg); |
| |
| lower_attributes_to_hw_regs(attribute_map, true); |
| |
| this->first_non_payload_grf = reg; |
| } |
| |
| void |
| gen6_gs_visitor::xfb_setup() |
| { |
| static const unsigned swizzle_for_offset[4] = { |
| BRW_SWIZZLE4(0, 1, 2, 3), |
| BRW_SWIZZLE4(1, 2, 3, 3), |
| BRW_SWIZZLE4(2, 3, 3, 3), |
| BRW_SWIZZLE4(3, 3, 3, 3) |
| }; |
| |
| const struct gl_transform_feedback_info *linked_xfb_info = |
| this->prog->sh.LinkedTransformFeedback; |
| int i; |
| |
| /* Make sure that the VUE slots won't overflow the unsigned chars in |
| * prog_data->transform_feedback_bindings[]. |
| */ |
| STATIC_ASSERT(BRW_VARYING_SLOT_COUNT <= 256); |
| |
| /* Make sure that we don't need more binding table entries than we've |
| * set aside for use in transform feedback. (We shouldn't, since we |
| * set aside enough binding table entries to have one per component). |
| */ |
| assert(linked_xfb_info->NumOutputs <= BRW_MAX_SOL_BINDINGS); |
| |
| gs_prog_data->num_transform_feedback_bindings = linked_xfb_info->NumOutputs; |
| for (i = 0; i < gs_prog_data->num_transform_feedback_bindings; i++) { |
| gs_prog_data->transform_feedback_bindings[i] = |
| linked_xfb_info->Outputs[i].OutputRegister; |
| gs_prog_data->transform_feedback_swizzles[i] = |
| swizzle_for_offset[linked_xfb_info->Outputs[i].ComponentOffset]; |
| } |
| } |
| |
| void |
| gen6_gs_visitor::xfb_write() |
| { |
| unsigned num_verts; |
| |
| if (!gs_prog_data->num_transform_feedback_bindings) |
| return; |
| |
| switch (gs_prog_data->output_topology) { |
| case _3DPRIM_POINTLIST: |
| num_verts = 1; |
| break; |
| case _3DPRIM_LINELIST: |
| case _3DPRIM_LINESTRIP: |
| case _3DPRIM_LINELOOP: |
| num_verts = 2; |
| break; |
| case _3DPRIM_TRILIST: |
| case _3DPRIM_TRIFAN: |
| case _3DPRIM_TRISTRIP: |
| case _3DPRIM_RECTLIST: |
| num_verts = 3; |
| break; |
| case _3DPRIM_QUADLIST: |
| case _3DPRIM_QUADSTRIP: |
| case _3DPRIM_POLYGON: |
| num_verts = 3; |
| break; |
| default: |
| unreachable("Unexpected primitive type in Gen6 SOL program."); |
| } |
| |
| this->current_annotation = "gen6 thread end: svb writes init"; |
| |
| emit(MOV(dst_reg(this->vertex_output_offset), brw_imm_ud(0u))); |
| emit(MOV(dst_reg(this->sol_prim_written), brw_imm_ud(0u))); |
| |
| /* Check that at least one primitive can be written |
| * |
| * Note: since we use the binding table to keep track of buffer offsets |
| * and stride, the GS doesn't need to keep track of a separate pointer |
| * into each buffer; it uses a single pointer which increments by 1 for |
| * each vertex. So we use SVBI0 for this pointer, regardless of whether |
| * transform feedback is in interleaved or separate attribs mode. |
| */ |
| src_reg sol_temp(this, glsl_type::uvec4_type); |
| emit(ADD(dst_reg(sol_temp), this->svbi, brw_imm_ud(num_verts))); |
| |
| /* Compare SVBI calculated number with the maximum value, which is |
| * in R1.4 (previously saved in this->max_svbi) for gen6. |
| */ |
| emit(CMP(dst_null_d(), sol_temp, this->max_svbi, BRW_CONDITIONAL_LE)); |
| emit(IF(BRW_PREDICATE_NORMAL)); |
| { |
| vec4_instruction *inst = emit(MOV(dst_reg(destination_indices), |
| brw_imm_vf4(brw_float_to_vf(0.0), |
| brw_float_to_vf(1.0), |
| brw_float_to_vf(2.0), |
| brw_float_to_vf(0.0)))); |
| inst->force_writemask_all = true; |
| |
| emit(ADD(dst_reg(this->destination_indices), |
| this->destination_indices, |
| this->svbi)); |
| } |
| emit(BRW_OPCODE_ENDIF); |
| |
| /* Write transform feedback data for all processed vertices. */ |
| for (int i = 0; i < (int)nir->info->gs.vertices_out; i++) { |
| emit(MOV(dst_reg(sol_temp), brw_imm_d(i))); |
| emit(CMP(dst_null_d(), sol_temp, this->vertex_count, |
| BRW_CONDITIONAL_L)); |
| emit(IF(BRW_PREDICATE_NORMAL)); |
| { |
| xfb_program(i, num_verts); |
| } |
| emit(BRW_OPCODE_ENDIF); |
| } |
| } |
| |
| void |
| gen6_gs_visitor::xfb_program(unsigned vertex, unsigned num_verts) |
| { |
| unsigned binding; |
| unsigned num_bindings = gs_prog_data->num_transform_feedback_bindings; |
| src_reg sol_temp(this, glsl_type::uvec4_type); |
| |
| /* Check for buffer overflow: we need room to write the complete primitive |
| * (all vertices). Otherwise, avoid writing any vertices for it |
| */ |
| emit(ADD(dst_reg(sol_temp), this->sol_prim_written, brw_imm_ud(1u))); |
| emit(MUL(dst_reg(sol_temp), sol_temp, brw_imm_ud(num_verts))); |
| emit(ADD(dst_reg(sol_temp), sol_temp, this->svbi)); |
| emit(CMP(dst_null_d(), sol_temp, this->max_svbi, BRW_CONDITIONAL_LE)); |
| emit(IF(BRW_PREDICATE_NORMAL)); |
| { |
| /* Avoid overwriting MRF 1 as it is used as URB write message header */ |
| dst_reg mrf_reg(MRF, 2); |
| |
| this->current_annotation = "gen6: emit SOL vertex data"; |
| /* For each vertex, generate code to output each varying using the |
| * appropriate binding table entry. |
| */ |
| for (binding = 0; binding < num_bindings; ++binding) { |
| unsigned char varying = |
| gs_prog_data->transform_feedback_bindings[binding]; |
| |
| /* Set up the correct destination index for this vertex */ |
| vec4_instruction *inst = emit(GS_OPCODE_SVB_SET_DST_INDEX, |
| mrf_reg, |
| this->destination_indices); |
| inst->sol_vertex = vertex % num_verts; |
| |
| /* From the Sandybridge PRM, Volume 2, Part 1, Section 4.5.1: |
| * |
| * "Prior to End of Thread with a URB_WRITE, the kernel must |
| * ensure that all writes are complete by sending the final |
| * write as a committed write." |
| */ |
| bool final_write = binding == (unsigned) num_bindings - 1 && |
| inst->sol_vertex == num_verts - 1; |
| |
| /* Compute offset of this varying for the current vertex |
| * in vertex_output |
| */ |
| this->current_annotation = output_reg_annotation[varying]; |
| src_reg data(this->vertex_output); |
| data.reladdr = ralloc(mem_ctx, src_reg); |
| int offset = get_vertex_output_offset_for_varying(vertex, varying); |
| emit(MOV(dst_reg(this->vertex_output_offset), brw_imm_d(offset))); |
| memcpy(data.reladdr, &this->vertex_output_offset, sizeof(src_reg)); |
| data.type = output_reg[varying][0].type; |
| |
| /* PSIZ, LAYER and VIEWPORT are packed in different channels of the |
| * same slot, so make sure we write the appropriate channel |
| */ |
| if (varying == VARYING_SLOT_PSIZ) |
| data.swizzle = BRW_SWIZZLE_WWWW; |
| else if (varying == VARYING_SLOT_LAYER) |
| data.swizzle = BRW_SWIZZLE_YYYY; |
| else if (varying == VARYING_SLOT_VIEWPORT) |
| data.swizzle = BRW_SWIZZLE_ZZZZ; |
| else |
| data.swizzle = gs_prog_data->transform_feedback_swizzles[binding]; |
| |
| /* Write data */ |
| inst = emit(GS_OPCODE_SVB_WRITE, mrf_reg, data, sol_temp); |
| inst->sol_binding = binding; |
| inst->sol_final_write = final_write; |
| |
| if (final_write) { |
| /* This is the last vertex of the primitive, then increment |
| * SO num primitive counter and destination indices. |
| */ |
| emit(ADD(dst_reg(this->destination_indices), |
| this->destination_indices, |
| brw_imm_ud(num_verts))); |
| emit(ADD(dst_reg(this->sol_prim_written), |
| this->sol_prim_written, brw_imm_ud(1u))); |
| } |
| |
| } |
| this->current_annotation = NULL; |
| } |
| emit(BRW_OPCODE_ENDIF); |
| } |
| |
| int |
| gen6_gs_visitor::get_vertex_output_offset_for_varying(int vertex, int varying) |
| { |
| /* Find the output slot assigned to this varying. |
| * |
| * VARYING_SLOT_LAYER and VARYING_SLOT_VIEWPORT are packed in the same slot |
| * as VARYING_SLOT_PSIZ. |
| */ |
| if (varying == VARYING_SLOT_LAYER || varying == VARYING_SLOT_VIEWPORT) |
| varying = VARYING_SLOT_PSIZ; |
| int slot = prog_data->vue_map.varying_to_slot[varying]; |
| |
| if (slot < 0) { |
| /* This varying does not exist in the VUE so we are not writing to it |
| * and its value is undefined. We still want to return a valid offset |
| * into vertex_output though, to prevent any out-of-bound accesses into |
| * the vertex_output array. Since the value for this varying is undefined |
| * we don't really care for the value we assign to it, so any offset |
| * within the limits of vertex_output will do. |
| */ |
| slot = 0; |
| } |
| |
| return vertex * (prog_data->vue_map.num_slots + 1) + slot; |
| } |
| |
| } /* namespace brw */ |
